Potent a–Glucosidase inhibitory activity of some Ziziphus plants

Abstract

–Glucosidase inhibitory activity of crude extracts of four Thai Ziziphus plants was investigated using the root bark and stem bark of Z. cambodiana, the root and stem bark of Z. mauritiana, the root of Z. oenoplia var. oenoplia and the stem bark of Z. oenoplia var. brunoniana. The results showed that the MeOH extracts displayed high potent –glucosidase inhibitory activity with IC₅₀ range of 0.007±0.006 – 0.031±0.0018 mg/mL, about 79 – 350 folds more potent than standard drug acarbose. While the EtOAc extracts possessed IC50 ranges of 0.014±0.001 – 8.772±0.234 mg/mL in the same test. Column chromatographic isolation and TLC screening led to obtain betulinic acid (1) as major product from EtOAc extract and highest quantity of tannin was found in MeOH extracts. Compound 1 (IC₅₀ of 0.031±0.0027 mg/mL) exhibited 79.2 times more potent –glucosidase inhibition than that of acarbose. This work is the first report of –glucosidase inhibitory property of Thai Ziziphus plants crude extracts.